Well if you enjoy it allot (seems you do), and have some money to spend on it, as well as somewhere that does walk on days near by, then by all means. Go for it!
Tips:
first thing you should buy: A good Mask
2nd thing you should buy: A good Hopper
3rd: Probably a pack + pots & protection?
4th: Air tank + small accessories (such as squeegy etc)
5th: Gun
that way you can still rent if you can't want, but use your own equipment if the place lets you.
This video helped me and is what i based my reply on:
but it is expensive to start up. I recently just have, with most 2nd hand bits, few new & it costs quite a bit to get you set up, (so much better with some 2nd hand stuff! Seriously arm pads = £25 - £30 new, 2nd hand = £10ish BARGIN! Tip: try and get some stuff 2nd hand if you want to save some cash, just make sure the guy your buying off is cool + won't screw you over) depends on the person if they want some bits 100% shiney new =p
After getting the bits, Its just the cost of entry and paint. Thats it. Paints usually cheeper i find as well on walk on days.
Hope i've helped a bit and anyone more experianced then me, by all means edit/add to what i've said!