Only way is Virwox , be aware that They have high fees , also you need to buy always 0'02 btc minimum and withdraw always 0'02 btc minimum , I woul say that you need something between 15/11 euros or 20/25 dollars to buy those 0'02 btc .
Also when exchanging lyndendollars for Btc ALWAYS bid higher than the current price , I recomend bid the same that second order to sell Btc is asking , because if the first order is not fully completed you will find your money stuck if you where just for 0'02 btc . Be caruful with virwox , it works , it has high fees and it can be a money trap due to 0'02 minimum , also the first time you buy you will have to wait 48h until your withdrawal order is completed . They are not scamers , they will give you your Btc's , but under his terms .
tried that before and my money was stuck there, didn't know they have high fees and high minimum withdrawal.
I'll invest a little only, around 5$-10$ but really don't know how.