Usually accordion like skin irregularities settle out with time. It makes sense to wait several months. Under correction of the arm if far easier and safer to manage than overcorrection. Re-operative costs are can vary among surgeons and for various reasons. Regarding the swelling "bulge", a seroma (a collection of fluid) can occur, especially toward the elbow. The fluid may need to be drawn off by your surgeon.
Healing, $$$, Tight stitches...
Wound irregularities: Most of time all of these areas settle out. I recommend getting a roll of 1/4inch "paper tape". Apply the paper tape over the wounds and leave it in place changing it every couple of days. The paper tape helps with the smoothing out process. I would try to use the paper tape for at least 6 weeks. (There are several research papers on the use of paper tape in treating scars) ...if this sound a bit strange.
$$$: Every doctor is different about the revision policies. Only he or she will be able to answer that one.
Tight stitches. Stitches can be pulled to tight, and in some cases, can cut off the blood supply to the tissue causing wound problems. That rarely happens to a well trained plastic surgeon, but it can.
Hope those answers help.
Lumps and bulge after arm lift
Great question! Yes, this is perfectly normal. You are still in the healing process, but I recommend that you do minimal activity for at least two weeks to aid in the healing process.
Lumpiness of scars after an arm lift
Some lumpiness of the incision line after an arm lift is normal. Given time this will resolve. Massage will help.
Thank you for the pictures. This looks like typical closure for body contouring procedures as his arm lift. The skin will settle out this move down over time. It will take months. Revision policies differ from office office you just have to discuss this at the appropriate time with your surgeon. Good luck