5'4" and 104 lbs - Extended tummy tuck or full tummy tuck? (photo)

Extended, depending on your definition, does not appear to be necessary. The incision needs to be long enough to treat the entire anterior abdominal surface and redistribute the excess skin, of which there is a lot, the excess being primarily in the lower abdomen. The incision goes from one mid-axillary line to the other, the hinge point from which the anterior skin can be lifted and brought down and redraped without a dog ear.
Despite there being a lot of redundancy when you are sitting down, it is certainly not so evident when you are standing up; the point being, that you may not have enough upper abdominal laxity to pull down enough skin to remove the umbilical donor site. The donor site may require closing as a vertical incision in the lower abdomen.
The length of the incision as described sounds like just a surgical decision and not an "upsell". Such a decision on length of incision should not influence the fees charged, whatsoever.
One doctor's usual tummy tuck may be another's "extended". The main thing is that the scar not be visible in a bikini. If the doctor marks the bikini with the patient pulling up the lower abdomen and then flexes the thigh to make sure the markings go in the crease between thigh and torso, and designs the incision within those markings, the scar will never be visible post-op.
With regard to terminology, a "full" abdominoplasty means dissection vertically up to the upper abdomen/rib area, as opposed to a "mini" which is dissection only up to the umbilicus. Extended refers to the length of the horizontal abdominoplasty incision, which in my practice is from mid-axillary line from one side to the other. Any "extension" would be posterior to this line, which is not commonly needed. Extending it all the way around is a lower body lift.

Thanks for your question! I don't think an extended tummy tuck is necessary. I also think that you may be able to avoid a lift depending on the implant you select. Some of that comes down to personal preference and wish pics. It wouldn't hurt to seek another opinion! Good luck!

We would need to see additional pictures, specially, from your lower back to be able to determine if the best option for you would be a circular tummy tuck because of the condition of the skin is the same as you have in your abdominal area then the answer would be yes that would give you the best outcome. Additionally, the benefit of it is also it gives you an automatic butt lift. Otherwise, if you do have the same condition of the skin in the back, and you only do a limited incision, you can be left behind with dog ears, which is essentially skin protrusion past the incision line.