Hi,
as you have said yourself, 100 is necessary and probably the cheapest way of getting data online (via Meteobridge)
That leaves you with 150 USD, which is going to be porbably just enough for something like I have, which has about 30s update intervals and no lightning detector - and as I mentioned previously, only very few stations will have this, vast majority of people use this separately and I am not sure how well Meteobridge works with this.
Bottom line - with your 250 budget, I dont think it is possible to get Meteobridge (license +HW), lightning detector and a good station with fast updates. Its just not enough. My budget was even lower, but I dont have 10s updates (meteobridge allows this, but my station does not have such fast update intervals) and I dont have lightning detector.