When the vendor lets you export your data in a form that you can easily import into your own copy of the exact same software, I fail to see how that is "lock-in". If the vendor increase the cost of the service or changes other terms in a way that's unfavorable to you, you can easily leave, that's the opposite of lock-in.
You can't really accuse a vendor of lock in just because his product is priced lower than it would cost you to do it yourself.
I think that's a very rigid definition of "lock-in" that implies it must be done with some anti-competitive malice. That's not how I've encountered the term in my past, so I'm welcome to other interpretations.
Per (not authoritative, obviously) wiki:
"In economics, vendor lock-in, also known as proprietary lock-in or customer lock-in, makes a customer dependent on a vendor for products and services, unable to use another vendor without substantial switching costs."
I agree with this. It shouldn't require that the service is purposefully preventing you from changing; lock-in can occur because a service offers advantages that prevent changing by virtue of some other cost.
"lock-in" implies some sort of lock. "I don't won't to leave because the service saves me so much money" is not a lock, you can leave, you just choose not to because it's better for you to stay. And if the vendor increases his price you can just take your data and go - your same application will run on another vendor's hosted MySQL instance.
If I say I'll pay you $1 if you sit in my office for an hour, you can't say that you were "locked in" by me, if Mary offers you $2 to sit in her office, you can walk over to her office and get more money.
That definition makes it very clear why people are disagreeing with you. Switching costs are those incurred by the difficulty of switching, and not the marginal cost of one provider or another. If internet provider A is $80 / month, and provider B is $60 / month, the switching cost has nothing to do with the $20 monthly discrepancy, or any speed differences, and rather represents how easy it is to cancel my subscription by being on hold for hours or cancellation fees.
