The price of a musket in the late 17th was about five Spanish dollars (The Buccaneer's Realm by Benerson Little, p. 251) or sometimes as much as three pounds (one pound was equal to four Spanish dollars) which was the equivalent of at least several months wages for an average skilled worker in European society (The Republic of Pirates by Colin Woodard, p. 34), so I imagine it would have been pretty difficult for Indians with limited natural resources to trade for muskets.

From my readings about buccaneers in Central America in the late 17th century I know bows and arrows were still very commonly used by Indians fighting alongside the Spanish in the Isthmus of Panama in the 1670s and they were still being used there in the 1680s. On the Pacific coast of Southern Mexico in the 1680s around the state of Colima, the English buccaneer William Dampier wrote that the Spanish often had guns but that mestizos and mulattos and blacks fighting with the Spanish were more commonly armed with swords and spears/lances and the Indians used bows and arrows. There seems to have been a shortage of guns in general. Some quotes from A New Voyage Round the World by William Dampier published in 1697 about events in 1685-86:

In this action, the Foot, who were armed with Lances and Swords, and were the greatest number, never made any attack; the Horsemen had each a brace of pistols, and some short Guns. If the Foot had come in, they had certainly destroyed all our Men.

...

There they found a company of Spaniards and Indians, who made head against them, but were driven out of Town after a shore Dispute. Here our Surgeon and one Man more were wounded with Arrows ...

...

Before they returned, Captain Swan and his other Men at the Town, caught a Prisoner, who said, that there were near a thousand Men of all colours, Spaniards and Indians, Negros and Mulatto's, in Arms, at a place called St. Jago, but three Leagues off, the Town on this River; that the Spaniards were armed with Guns and Pistols, and the copper-coloured with Swords and Lances.

In another encounter on the Pacific coast of Central America around Nicaragua, a landing party of a dozen buccaneers was ambushed by 40 or 50 Spaniards who drove them to take refuge by wading out to a large rock some distance from shore. The Spaniards waited for seven hours hoping for them to be drowned by the tide but never attacked and stayed hiding in the bushes because Dampier says they only had three or four guns between them, the rest being armed with lances:

The Spaniards in these parts are very expert at heaving or darting the Lance; with which upon Occassion, they will do great Feats, especially in Ambuscades: And for their good Will, they care not for fighting otherwise, but content themselves with standing aloof, threatening and calling Names, at which they are as expert as any others; so that if their Tongues be quiet, we always take it for granted they have laid some ambush.

I also know when the British attacked the city of Cartegena in Columbia in 1741, the Spanish levied hundreds of Indian archers to fight for them. I don't know exactly when they became completely obsolete in Central America but I think it was a very long process and depended greatly on location. Even some Europeans on the fringes of Ireland and Scotland fought with bows and arrows into the 1630s and North American Indians used them into the late 19th century. Obviously that's not in Mesoamerica but I think it shows that when people don't have access to guns they usually use bows and arrows as long as that technology hasn't been lost yet. I don't know much about the conquest of Petan in the 1690s, but it makes total sense that they wouldn't have access to guns living in an unconquered region with little exposure to Europeans.

However, I also know that some Indians at this time did use guns and they seem to have preferred them when they could get their hands on them. William Dampier wrote about how English buccaneers in the 1680s were friendly with Miskito Indians in Nicaragua and they worked with each other because of their mutual hostility toward the Spanish. The buccaneers developed an agreement with the Miskito where they would bring a few young men along with them on their voyages for a couple of years because they were very valued for their hunting and fishing skills and in return the buccaneers would teach them things and give them muskets. These Miskito seemed to have really liked muskets and Dampier writes that they "always bore arms among the Privateers" and became very good shots. One of them was given the name Will and accidentally marooned alone on the Juan Fernandez Islands off the coast of Chile for three years in the 1680s, and after running out of gunpowder he was able to melt down his musket barrel and fashion harpoon tips and other tools for himself which Dampier says he learned from the English. Dampier writes that other Indians who hadn't learned ironworking from the English still used stone axes and tools.