Does average beer nowadays tastes better than it was in the past(century or two or five etc. ago). I mean ingredients and recipe wise. And if so how different was the price?
Taste is a very difficult quality to put into historical perspective. The best we have to work with are descriptions of contemporary writers on the taste, but they are obviously biased by their own experience and that experience is per se tied to the time frame. This makes it impossible to compare those descriptions with current beers, as they would not be familiar with the beverages we make nowadays.
Alternatively, historical brews that people make today based on written recipes (f.i. Dogfish Head Ancient Ales) are inherently problematic as assumptions are made on the method of production that are not proven to be authentic. Whilst often ingredients are written down there's al lot about the production of the beer that isn't. For instance cooking schedules and when certain ingredients are added to the boil. This means that we can't say for sure that any beer based on historical recipes actually tastes like the beer that they would've made.
Those rather disappointing facts aside there are some things we can say of historical beers that provides some idea, in a very generalized way, about the taste of beer. The main thing is that we have a way better understanding about how the process works.
The 19th century, with it's many revolutions, also revolutionized how beer was made. First and foremost was the isolation of yeast cells by Louis Pasteur. Brewers in history had some general concept about what yeast was and what it did, enough for them to practically make beer. But the microbiological funcion of yeast and other bacteria was unknown.
So the beers that were made prior to the 19th century weren't produced in a closed environment like our current brewing process. This meant that infections by bacterii and the presence of wild yeast strains would have most likely affected the taste.
Secondly there was no effective temperature regulation and therefore a brewer was always affected by seasonal shifts in ambient temperature. Some beers, like the lower fermenting lager/pilsner types could only be made in autumn/winter. Some brewers would store large amounts of ice in caves/thick walled structures in order to be able to brew for a longer time.
So the invention of the mechanical refrigerator revolutionized how beer was made. The rise of the populartity of the lager/pilsner type beers in the late 19th, beginning 20th century was caused by the clear (filtered), clean tasting (fewer esters and sour tasted from infection), cold (refrigeration) qualities of this beer type. These are considered 'normal, regular lager' to us today, but back then it was revolutionary.
The fun thing about the current craft beer boom is that people increasingly get interested in the formerly considered defects that this lager/pilsner fixed. Sour beers with lactobacillus or acetobacter are popular with beer geeks as they are tastes that we dissociated with beer flavor due to a century of drinking lager/pils. Those are tastes that would have been present in historical beers that we know how to control nowadays.
So the one thing that can be concluded about historical beer vs current beer is that, today, we have a vastly better understanding of the process of making beer and we have the means to control every part of it. This means that modern beer is way more consistent and lacking in defects (generally, there are still brewers out there that make basic mistakes). So the modern brewer should be able to make a way more consistent and uninfected product than any brewer in history before the 19th century.
That being said the standard beer people drank in history would most likely not taste very good to our tastes. Cheap beer, historically, would have been a second run of the grains and thus quite low in alcohol and in quality. Most likely cheap beer today is way better than beer in any point in history, but there is no objective way of really comparing those objectively.
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