Gosh, I hope colleges don't find out about this pricing strategy.
They've been doing it for years; it's called "financial aid". It is literally the textbook example of how to get people to pay different amounts for the same thing based on what they are willing or able to pay.
It's also why the recent shift in immigration policy has affected top-tier universities so much: domestic education is, by and large, subsidized by international students who are almost exclusively admitted on a need-aware basis, allowing the schools to ensure the financials work out on paper.
Now that there's been a huge drop in international applications, they need to make up the loss in revenue, so they're shifting those costs back to domestic applicants.
I can hardly claim omniscience but my understanding is that by and large universities bin students into broad categories and apply a uniform rate schedule based on demonstrated financial need (plus academic performance in some limited cases), with international students generally billed at the highest rate.
The thing is nobody will pay more than the advertised price so they want to not list a higher price, and then offer discounts. They do it via coupons and other mechanisms, but they'll never get anyone to pay $20 for a $5 bottle of Coke.
A coupon that you must be over a certain age to redeem is an entirely different beast than one which was sent only to you specifically with an individualized price based on opaque criteria aimed at directly and immediately optimizing revenue. It is entirely possible to outlaw the latter (though Maryland appears to have failed to accomplish that) without restricting the former.
Or, gasp, cut bloat.