I'd be sad too if I couldn't afford to go abroad. It's very much a first world problem, but it's something we really enjoy as a family, and I'd feel like We were missing out if we couldn't.
I never went abroad with my parents as a child, and I did feel we were missing out to an extent. Also it's only the last few years that we have been able to afford to take our kids, and I felt that they were missing out that we couldn't afford to take them. We had holidays in this country that we enjoyed, but felt sad that they'd never been on a plane, or experienced another country.
Obviously your kids have plenty of times, it's just this year that you're having to give it a miss. Hopefully you'll have a good week weather wise, if you do you will have a great time on sure, the UK is beautiful in the sunshine, it's just a bit of a gamble.
By the way, we've never spent more than £2000 on a holiday abroad. This years was £1300 in an apartment for a week, £1450 with transfers and extra baggage. We will take about £1000 to spend, but could take a lot less if we had to and could easily have done everything including spends for the £2000 you're spending in U.K.