I think the steps are
(1) get an updated hearing test. Get a copy
(2) if your hearing loss is mild to moderate then sure, try an OTC. If you do, please ensure you can return them with no fees. If it is not mild to moderate , you will need professional advice. (3) Based on what you said, Costco is the best option if you don’t want to spend more than $1600 and your hearing loss is not mild to moderate .
OTCs are only helpful for mild to moderate hearing loss, hence my recommendation to do a bit of homework before spending money on them .
If your previous hearing aids were not helpful, most likely they were not programmed correctly.