Please give me advice about handy but not too costly stroller. The old stroller is too big and heavy for me and hard to assembly!

I would like to recommend BabyZen Yoyo. It is really very easy to use and push around. It is light weight too, about 6 kg and my 2.5 years old toddler still sitting in it (he is about 12kg now). What I like most about this stroller is it can be fold into very compact size and carry like a bag. This is very convenient especially when I am travelling alone with 2 kids and taking cab (no need to put stroller at the taxi boot). I brought this stroller to Hong Kong and it was very convenient to be carried around. There is an alternative and similar design which is YoYa, manufactured in China and my friends commented the features and functions are very similar to Yoyo, it costs much cheaper (about $200) and can be purchased from qoo10.com

I have combi and the yoyo inspired, yoya stroller which I got from taobao. Though both are one hand fold, yoyo inspired is more compact and better sized. But seating wise, they yoya can't recline fully and is hard for my girl to sleep. Though it is a five point harness, my lo can rock her body and the seat shows slight movement and the harness actually causes discomfort to her while she fell asleep.

If you are not picky on brands, you can get this stroller from qoo10. It is a replica of Yoyo stroller. It is compact and light with various designs. http://list.qoo10.sg/item/BEST-SELLER-ICHIGOBABY-LIGHTWEIGHT/423393708?stcode=77