While I cant give you any advice on funding... for eyebrow lift, there are few different approaches. One is endoscopic, you already mentioned. Then there is coronal incision approach, and lastly hairline incision approach. Which one best option varies from one patient to another. Endoscopic is least invasive, but it also have its limitations. If there is little extra skin, and you only need a subtle lift effect, you are ideal candidate for endoscopic approach. If you need more lift, and you have more sagging skin, the other two might be better choice, as strip of skin gets removed, either on top of scalp with coronal, or at hairline with hairline approach. With endoscopic approach your hairline gets set more back, with coronal even more back. With hairline approach, hairline can be lowered, aka hairline advancement. Correct diagnosis of problem is very important here. Another thing is, if you have extra skin in eyelid area, it might not be possible to resolve with only eyebrow lift. Surgeons often combine upper eyelid blepharoplasty with eyebrow lift to give the best results. Many aspects, such as shape of the eyes, orbital ridge shape and distance from the eye, distance between eyebrow and hairline, eyelid skin, underskin fat layer, etc, need to be taken into account.
Price for simple eyebrow lift isnt too much. Its one of procedures that can be done in surgeons "office" under local anesthesia and sedation, not necessarily in operating theatre under GA. So this reduces the cost. Im not familiar for prices in UK, but prices in Europe can be anywhere from 1000-3000 eur, or more. I suggest you consider if eyebrow lift is the only change you feel you need, in upper face area. You might only be bothered by soft tissue now, as this is what you are focused now. For example orbital rims, and forehead shape&projection...