Advice?

I could use a little advice about moving forward with my fitness plans.

A little background: I'm most of the way through P90x (almost in week 11) and I've fallen in love with lifting weights. After I'm done with P90x I really want to do more with lifting. As a side note, I've already bought and read the New Rules of Lifting for Women book.

So here's my problem: I live in a super rural area outside of a big city, I seriously live next door to cows, and I've been making do with just the weights and equipment I have at home (some free weight dumbbells, medicine ball, exercise ball, pull-up bars), but I feel like I'm coming to the end of what I can do at home with what I have and still improve further. I know I really need to increase my weights and I'm trying to decide whether I should invest the money in buying my own equipment or look for other alternatives.

Some options:

1. There's a local gym near my house that I could join for something like 55 EUR a month that has a decent selection of weights, weight machines and cardio machines, nothing spectacular or anything.
2. Buy my own equipment at home (barbell, weight plates, more dumbbells, resistance bands, etc). Everything that I've been looking at would probably run me between 250 and 500 EUR, minimum
3. I've been looking into Cross Fit and there's 2 Cross Fit places in the city. One is 70 EUR per month and the other is 90 EUR per month. I would also have to take at least a 30 min train ride there to work out, which I'm not opposed to, but that definitely adds a cost and time factor.

Any thoughts?