At what point though does something become a believable price ? Seems a bit harsh to criticise the OP for believing £23 for 2 for 3 weeks , which is ridiculous but then finding the Tenerife price believable .
For me the dividing line is whether the quoted price is going to cover the price of the flight OR the price of the hotel. £117 pp would conceivably cover the flight to Tenerife, so opens the possibility that the TO was prepared to take a hit on the hotel in order to fill the plane even though I would personally assume that in the end I wasn't going to get a good 5* hotel for the price and would expect them to say that was an error and at the very least chnGe the booking to a lowered adequate of hotel or make it non-AI. In the end of course the booker didn't get that holiday either for the originally quoted price. However, a price of less than £12 pp for 3 weeks longhaul is never going to cover the cost of either flight or hotel (even in Goa) and so I would never for one moment consider that to be a genuine offer. I might have tried to book at that price and see if they would honour it but I would never have assumed that it was anything other than a pricing mistake. Whether £117 for 2 weeks in Tenerife could be a genuine offer is probably debatable but £12 for 3 weeks in Goa is surely never believable? And both are different issues as to whether a TO should be expected to honour such gross underpricing.
SM