My two cents, speaking as someone who has been intensively involved in philately for only five years:
Assuming the price of two hamburgers is about $20, then what you paid for these is "okay." To evaluate "what was spent," consider these two options for procurement:
1) Search for collections or lots, which, over time, provide specimens for pennies on the dollar, compared to what you would pay when acquiring the same specimens one at a time. The downside to this is you accumulate a lot of dross - dozens if not hundreds of virtually worthless stamps for each "good" one you find.
Your space and time have value as well. You can get some relief by attempting to re-sell the remainders, almost certainly at a discount.... but it takes time and effort.
2) Seek out individual or small sets of stamps. Inform yourself first by looking at market prices for these. One way to do this is to use stamp smarter.com (worthy of a separate discussion). "Best prices" may be found on
ebay or Hipstamp.com (for example). You will pay more per stamp this way, but you are eliminating the clutter and extra work that the other option entails.
3) Trade with like-minded philatelists. A local stamp club is a plus, if available. I understand some folks here on stamp community.org trade/buy/sell with each other as well.
Hope this helps.