Honestly, I've had better luck over at KEH than MPB lately. Their grading system is super conservative, which is a lifesaver. Since you're tight on cash, check out these spots:

• KEH for their gold standard return policy
• Adorama for their certified pre-owned stuff I picked up a Sony A7III 24.2MP Mirrorless Camera there last month and it was basically flawless. Beats getting sensor dust surprises right before your trip, for sure.

TL;DR: Stick to B&H or official outlets for peace of mind. Honestly, MPB had me dealing with sensor dust last year and it was super annoying. I ended up grabbing my Sony A7III Full-frame Mirrorless Camera from the Sony official refurbished site instead. It cost a bit more, but at least the shutter count was super low. Don't risk a trip with janky gear. Just save yourself the headache.

Re: "Honestly, I've had better luck over at KEH..." - totally agree on the conservative grading. If you are really pushing it for time, I would look at the official Sony Alpha a7 III Full-frame Mirrorless Interchangeable-Lens Camera refurbs again if they pop up, as the 1-year warranty is peace of mind. If you need to save cash, check out the used listings on FredMiranda forums. The community there is super strict about history and shutter counts. You can often find a Sony A7 III 24.2MP Mirrorless Digital Camera from enthusiasts who take better care of their sensors than the big resellers. Another solid option is the Canon refurb site if you havent locked into the Sony ecosystem yet. The Canon EOS R Mirrorless Camera is usually priced pretty well and their refurb process is basically factory-new condition. Buying from the source is always less risky for sensor issues than third-party resellers.