Surfing Waves

Specifically, my board

I can't currently call it junk... I've been surfing with vigour for only the last month or so, and it's succeeded in allowing me to catch waves, and stand for as long as I'm able (turning being the next hurdle). So I suppose it would just be nice to have a probability, or timetable of when it's likely to break apart under me, lol.

-The tail is delaminating along the edge, and this delamination has worked its way up in a line next to the center fin (taped all up, currently).
-Crack, perpendicular to the stringer across half the board, near the middle, stemming from an apparent repair on the rail (one of a few)...
-A few (repaired and not repaired) dings and dents along the bottom.
-One fin appears to have seperated and been reattached a few times... At least one of these repairs seems to be slightly delaminating, but the fin is still sturdy, or at least as sturdy as the other one, lol.

So I don't really care about having the greatest board (and am broke in any case), but...

-How long til it breaks?
-At what stage in my ability will I actually get some sort of benefit to moving up to something less ratty, and what might those benefits be?
-It's a $50 Craigslist Con shortboard. Is it worth repairing (never mind if I got ripped off in the first place, haha)?

For reference, looks a bunch like below (flattering angle):

its hard to tell the extent of the damage by a photo - but it might be a worthwhile experience to try and get some repair experienc ein for future dings etc..

If it's like a trampoline, drips water all night after a surf, the fins carry on past you when you turn and / or you get 'glass splinters in your chest / legs - either have it looked at or retire it as a wall hanger of 'the good old days'.

Hope this helps