I've had four Abras. The first one I bought back in 1995 (along with a Drop A Card), and it was in decent condition (the DaC was very nice). I can't recall *why* I chose to sell it (and the DaC!), but I did. Well, I do recall actually. I bought another dozen games in 1996, so had to start cutting games loose.
I soon after realized the mistake I'd made in letting go of the Abra, and began a quest to replace it. Took three more Abras before finally getting a nice one again, and that one has stayed ever since. Probably will be the last title to leave too.
This one has 50,000-ish plays on the meter, and is nice enough all-around original (except for the bottom two plastics). I still see Abras pop up, but haven't found an upgrade yet (not really looking though either).
The thing I like about the game is that there are multiple ways to approach winning (drops, rollovers, bonus, score), a skill shot is required to reset the drops (not just an automatic reset), there are two ways to get the 1-4 sequence (so not just a plunger shot), everything can be done from flipper shots, and it has a progressive strategy. The flow is great, it's possible to make great ball saves, and the long distance drop target shots are very satisfying.
I've long thought it's been an underappreciated game, overshadowed by the other great '75 titles (El D., Atlantis), and the values have stayed low.
Downsides are the half-moon credit unit, and the use of particle board for the back of the cab. (So glad Gottlieb switched back to plywood a year or so later.)
As far as a value for the money type of game, I think Abra is a good example. Great player, not so expensive. (Yet.)