How much will you weigh with clothes and any stuff you are carrying? The reason I ask is normally btwin bikes have low weight limits. 100kg minus the weight of the bike which means you are looking at 85kg or less and even someone who weighs 75kg may not be within those weight limits by the time they are clothed and the stuff they are carrying especially if they have added other accessories to the bike.

If you are within the weight limits then I think its reasonable value for the components featured. Which country are you in? If the UK look at the Carrera folding bikes from Halfords which have much stronger frames and better components or maybe the Go outdoor compass folding bike. Seems good value with a cassette based drivetrain.

Compass Fast Forward Folding Bike | GO Outdoors