Can anyone suggest the best and cheapest way to connect stripe.com to quickbooks online?

Utilize the starter plan of this connector for free

https://www.integromat.com/?pc=quickbooks

Otherwise, you may explore this connector to reconcile Stripe transactions easily.

 https://synder.grsm.io/quickbooks

I would recommend Chargezoom. The only two-way sync approved by Intuit. 

Here is a link to their site. Stripe to QuickBooks Online Sync with Chargezoom