I haven't seen one at that price at WalMart. Prices starts at $88 there (in my area) for the NEC brand. It's not too late for layaway if you see one you want. They have Samsung ones for around $130 & up.
My suggestion is to go to a store where second hand items are available, or simply save for a new monitor. The positive of a new monitor is having a warranty for 1-2 years. Most places that sells previously owned items has only a non-DOA warranty at best, so if buying at such a place, carry a computer (a notebook if possible) to make sure it works.
I'm currently saving for a better one myself, one with a Display Port connection, 2 HDMI's & 1 DVD-D port (to use for 3 computers). Newegg has one such monitor available, in the ASUS brand.
$50 isn't going to buy a new monitor, unless it's something that was found still in the box in an office storage closet somewhere & forgotten about, or not needed. Even so, it'll be VGA at best.
Cat