Well, there are tons of good, wickedly good balls in the $100 - $150 range. Even in today's very expensive world that is fairly cheap, as sports equipment goes. 2 strike balls and one spare ball would be plenty for many 200 average bowlers who bowl in 2 houses and in 2 different leagues and in some tournaments, no matter how some of us talk about carting 6 or 8 balls to one league.
While it would be nice to have the simple life of urethane/plastic covers with pancake weight blocks again, technology goes forward, not backward. That said, there is no need for the average bowler to understand any of this. That is THE JOB for the driller/pro shop. It's an essentialpart of why you pay them. You should find a good one and have them recommend what they have or can get to suit what your needs are. Really!
On this website, we tend to talk technological details because we like to share knowledge and inform other bowlers who want that knowledge, but it is not essential, even if you average 225 in every house and every league.
Regarding simple cores, the vast majority of balls use symmetric cores, which have some very basic ways of drilling them. For the vast majority of bowlers, even good bowlers, the basic drillings, which are not that complicated, can be used. Again, One of the basic natures of this website is to get into the nitty, gritty details; so, sometimes, our discussions can get complicated. Don't allow that to confuse you.
For basic and complex issues, see a FAQ set up by one of people here.It took a lot of effort and there's a ton of data. Read it at your leisure.
http://home.mchsi.com/~s-cross-7-28-71/FAQ.htm