I live in a village just outside of Dover (which most on here wouldn't touch with a barge pole). I have a six bedroom semi detatched victorian house with a lovely garden in a beautiful little village. My children go to an outstanding preschool and an outstanding primary school. We live a 5 minute walk from two huge beautiful parks which people come from miles away to visit. We live a 5 minute drive from a lovely stony beach, which is never busy even in the height of summer (due to the stones). Dd sails at the local sailing school which is an amazing thing to be able to do. We have never had to go on a waiting list for any club or extracurricular activity. We have English heritage passes and go to Dover Castle all the time, which is really fun, they also love walking along the cliffs.
My bil and sil have just bought a beautiful 4 bedroom house in Sandgate for your budget. It is second row back from the sea, but is upside down so their sea views are amazing (I'm quite jealous!). They are minutes walk from the coastal park which is so lovely and a Beautiful sandy beach. Their local primary school is also outstanding.
The kids love Folkestone. There are these fountains on the sea front which they love running through on a hot day. And the beaches are lovely. I grew up around here and I remember walking along the cobbled streets back to the car with sandy bare feet eating an ice cream - it seemed idyllic to me. The harbour arm is lovely and lots more upmarket than other areas of Folkestone.
I love samphire hoe as well (the bit of land between Folkestone and Dover made from excavation for the channel tunnel). It is never crowded. There is a lovely nature walk that ends in a great rock pooling beach.
We live close to three zoos (Wingham, howletts, port lympe) which are all wonderful fun.
Margate is great for a day out, the beach can be crowded though, but the children love the penny pushers and the traditional sea side attractions.
I can do a day trip to France really easily.
I love where I live. It isn't without its problems. I don't like the selective school system (although it personally did me very well) , and as a leftie my vote will never count here! It is, like many costal towns, a bit deprived. Some areas are very run down. But you get an awful lot for your money and I think the quality of life is lovely. When I go to places like Brighton, I find the fact that it is so busy and I can't park anywhere really frustrating!