Selling Royalties vs. Keeping Them - Small Lease - Mansfield, TX

Back in 08 we signed an oil and gas lease with a company called wyldefire energy here in Mansfield,TX. Back then they were offering 15k per acre as a sign on bonus. Since we only live on .145 of an acre, our bonus was $2175. We have never gotten any royalty payments yet. Has anyone sold their royalties? From the estimations I’ve done, the very most we’d get is maybe $20 per month if we’re lucky. It might be a lot less. Since we have such little property, is it a good idea to sell or just hold on to it? Do you actually have to be getting checks before you can sell? I’m sure we won’t get more than a few hundred dollars maybe, but I’d don’t know if it will be better in the long run not to sell.