I guess if it were me I'd go with 1 STTNG machine, rather than having to arrange in my junior or senior year the moving of 9 machines.

If you want 9, go with 9.
If you want 1, go with the STTNG.

You could save up and get the STTNG when you have more than 1500, because in my opinion if you buy that pin for that amount of money it's not going to be in the best condition, and there most likely will be problems you have to fix on it. I'm thinking $3k should get you a pretty good STTNG, and possibly LESS things that need repairing on it.

Do you think you will get bored with just the one pin, and start wishing you'd bought the 9 pin deal?

Good Luck with getting your learn on!