I live in Topsham. Prices are sky high here. That house is in a nice road (quite a distance from the river and up a hill, so really no flood risk). The price might reflect the option to knock it down and build a dream home, but it might be in the conservation area, in which case it's just a whopping price!
Regarding your search for a location, we've been here for 30 years - came to uni in Exeter and never left - it's a great place to live. Topsham has a really great community feel. Tons of stuff going on for all ages. Open air community-owned swimming pool, good primary school (my son went there) and good choice of secondary schools in Exeter. You're at the end of the M5, Topsham has a half-hourly train service. You can be in London in about 2.5hrs, or on the beach in 15 mins. Fore Street has lovely independent shops and plenty of places to eat and drink. Every other year we do Topsham's Longest Table, where tables are set up the entire length of the main street and most of the town bring their own food and drink and have a brilliant boozy feast. There's live music on the quay in the summer, an active film society at Matthews Hall (town hall), Charter Day fayre in August and Christmas lights switch on. Loads of book clubs, if that's your thing, pilates/yoga and all that at two specialist venues, paddle boarding and sailing on the river, and six pubs including The Bridge Inn (world's most authentic pub, imo!).
Sure, there are other lovely places to live in the UK (with cheaper housing), but Topsham's pretty special. I hope you find your perfect home 🙂 x