One warning about KEH, though it’s not their fault. Depending on the value of the gear you sell to them, you may end up adding complexity to your tax return. If you opt to have them pay you via PayPal (or any business pays you that way, really) and the amount exceeds a threshold, that triggers a 1099-K form that you’d need to deal with at tax filing.
The threshold used to be $20,000, then it was lowered $600 for the 2023 tax year but there was an outcry and the IRS deferred implementation and it’s supposed to be $5000 for this tax year. BUT it varies by state, for example in MA they did not defer the implementation of the $600 threshold for 2023. I had made the ‘mistake’ of sending a lens to KEH and I got a 1099-K that I was able to ignore for federal tax but not state tax. Not a huge issue, since it’s a sale for a loss, but it meant more paperwork.
The lesson for me was if I sell to KEH, I select the option to have them mail me a check.
MPB pays via ACH (direct deposit to your bank account), so no worries there.