Blue Mics are without a doubt looked at as the go to for a quality USB Microphone and for that reason tend to be a little pricey but, Blue has released a USB Mic called The Blue "Snowflake". It is priced a little above your range of 30-40 euros but at $60 you almost cant beat it, especially for its quality. There are a few more reputable manufacturers of quality USB Microphones. Here's some different USB mics with good quality:
$59- Audio Technica-ATR2500 USB Condenser Microphone
$46- CAD U37 Studio Condenser USB Microphone
$39- BLUE Snowflake USB Microphone
$59- Behringer C-1U Studio Condenser Microphone with USB Interface
If This helps please let me know!
Lead Technician, AA Rental