Another, more inexpensive, route might be to go with a Tolino Shine (the original Tolino). GoodyStore (whom I've had good luck with) is currently advertising a couple Shines. They have SD slots and will go up to 32GB. They have a front-lit screen with 5 LEDs. The quality seems to be good. If you get an earlier one you'll get a Pearl screen, later ones came with E-Carta screens (212ppi in either case).
https://www.ebay.com/itm/Tolino-Shin...ox!83646!US!-1
The Buy It Now price is $30 (plus shipping and tax) but I'm pretty sure you could offer $25 (maybe less) and they would accept it. They've had these up for quite a while. The Shine is a good, solid Reader, especially if you add your own dark font. Pretty sparse interface, but Tolinos are now my favorite Readers. (If you do make an offer, be aware that they don't work on weekends.) The last eReader I bought from Goodys was ordered on Monday morning and arrived on Wednesday morning.