For heavy paper, I would avoid any printer that has to bend the paper
very much when feeding it. I've had paper get stuck in HP printers
that have to curl the paper all the way around when feeding it.
I also check for ink durability because most ink jet inks fade fast,
but this may not be a concern for student work.
I am pleased with my Epson Stylus C82 which has been replaced by
Epson with model C84. It handles heavy card stock okay (one sheet at
a time) and it uses inks that are water proof almost immediately.
They claim the inks to be archival up to 80 years. It only takes
paper up to 8.5 inches wide. Price is $99, but I have seen it
discounted about $20.
I order inks and paper from Atlex.com for a slight saving on brand
name inks and paper.
When I need a large high quality print, I use a friend's Epson Stylus
Pro 7600 printer. He uses 24 inch heavy weight archival roll paper.
He prints some digital photos six feet by two feet. The printer is
$3000. His cost for consumables is $1 per square foot.