Well... yeah they'll go together, but I wouldn't recommend it. I don't think the angel would fare very well.
And you can't get much as far as aquariums go for $50, unless you look for used stuff, yardsales and what-not. $50 will buy you a new...
tank up to 29g
or one heater
or one filter
or lights/hood
or a stand for 29g or less
or a variety of little things like thermometers, nets, de-chlor, ect.
If you go 10g you could possibly get two of those items.