Hello,
If you don’t need the money I’d hang onto it. The lease bonus may eventually be more than what is currently being offered. Plus any royalties from production that might come could be even higher than the initial lease bonus. As for taxes you would have to pay income tax on the lease bonus and any royalties. I don’t know if Mississippi has a State income tax but they probably do and you would most likely have to pay State taxes as well. As for Texas taxes the only tax is the yearly Borden County tax from the tax assessor-collector for Borden County. Cost depends on on your % interest in the well as well as production. We have some Borden County mineral interests and the County taxes have not been that high.
Good luck. You’ll have to pay Capitol Gaines taxes on selling your interest I believe. No matter what the tax office always gets their cut of any type of sell/lease/production income.