is it because of cost effectiveness or lack of features? if not what should I prefer to buy?

>As a beginner to hardware wallets what should I start with?

Not ledger... 

Jade, Seedsigner an old phone are better options than ledger.

Bitcoiner1

tech

Ledger Stax™

Best For: Users looking for premium security with an advanced touchscreen experience.

Features: 3.7” curved E Ink® touchscreen for an intuitive display. USB-C, Bluetooth®, and NFC connectivity. Wireless Qi charging for added convenience. Protective Ledger Magnet Shell included. Supports thousands of cryptocurrencies and NFTs. Ledger Live app compatibility.

But I don't think it is better than Ledger Flex. As a beginner to hardware wallets what should I start with?