Tusheti is closed for the winter, and the road is the reason

Neither source gives fixed dates, because there are none: the opening depends on when the snow clears and the closing on when it returns. The guide's window of mid-June to late September and Wikipedia's mid-October to mid-June closure describe the same thing from opposite ends. For a tour operator that means Tusheti itineraries cannot safely be sold for May or early October, and for a traveller it means booking a guesthouse without checking the road's status that week is a gamble on weather you cannot see from abroad.

The main road to Omalo is about 70 kilometres long and crosses Abano Pass, with the guide putting a realistic maximum speed around 30 km/h. Kvemo Alvani to Omalo takes five to six hours; the whole journey from Tbilisi is roughly 190 kilometres and about eight hours with stops. A 4WD vehicle is required, phone reception is patchy, and most rental contracts in Georgia specifically prohibit taking their cars up there, which is the detail that catches self-drivers out.

The guide's figures: a marshrutka from Tbilisi's Ortachala station to Telavi or Alvani runs 12 to 15 lari, with roughly three departures a day. A shared sedan taxi is about 20 lari to Telavi and 30 to 35 to Alvani. The mountain leg is the expensive part, about 100 lari a person in a shared minivan from Kvemo Alvani into Tusheti, or a similar amount for a guesthouse-arranged transfer, plus another 100 to 150 if you start in Tbilisi. A private taxi from Omalo to Dartlo was 200 to 250 lari for the car.

Prices in a travel guide age, and this one was last updated in January, so treat the lari figures as orders of magnitude rather than quotes. Two timing details are worth keeping: shared taxis up to Tusheti tend to leave Alvani between about midday and three in the afternoon, and the return marshrutkas from Alvani to Tbilisi include one at two o'clock. Both mean the mountain leg wants a whole day of its own, and that an early start from Tbilisi is not optional.