Kate, well done! Keep it up and ignore the naysayers.
Asitis, please consider that although 5 km might not seem much to you now (well done you ????) it possibly did when you were starting out. What possible good do you think you are doing by discouraging someone from becoming involved in our sport?
I'm very happy with a Horizon T4000 - it folds, which is handy, but seems pretty solid (it was herniatingly heavy to move the box it came in, but has wheels to help when assembled) and I've had no problems with it (several months of regular use, including a few 20-milers). No bells or whistles, but does everything I need (max gradient 12 %, max speed 20 kph). They are apparently permanently reduced from their "recommended" £1500 price tag, which, to be honest, would possibly be a bit steep.