You might want to check out the inflatable hot tubs made by the [ company name removed ] company. They have models which have 5 inch thick foam walls, which come in 8 sections. This means that if there was an issue with one of the sections, it'd be relatively easy to deal with if you went down the "hole" route. It's pretty heat efficient, because of the foam walls, and the jets are pretty strong too. It'll set you back about £750 but still cheaper than a rigid hot tub.
edited to remove reference to the supply company. Please PM Bo if you need further details.
