is this a “viable” workaround to get monthly installments with low credit limit?

[leanddjbbdbbchdabcdes]

I want the new iPhone SE but my limit is only $250 because I’ve just started using credit... is there any risk in selecting trade in to bring the price down enough to qualify for the installments but knowing the trade in won’t reach full value because it doesn’t meet all the requirements? See my current phone if at full Trade in value Would bring the price down enough to qualify but because it won’t meet all the requirements it offers a lower value which then means I don’t qualify for the installments because its just barely above my credit limit if I submit it with lower value. So assuming the site lets me place the order because I said it was in good condition and therefore worth full trade in value what happens when they realize it doesn’t actually meet the requirements? Do they charge me for the difference after because it’s not worth full value like I said? And since my card is after buying the phone already maxed out would it be possible they allow a different payment method to cover the difference? And is there any legal trouble I could get into by trying this? If there’s a possibility of legal trouble I would obviously scrap the plan but it wouldn’t be like I don’t send a trade in AT ALL...