28 days short of 5 years on my Tier 2 visa, can I apply for ILR instead of Tier 2 extension?

I came in UK on Tier 4 Dependant visa in Sep 2012 and was then sponsored by my employer in UK at later stage. My current visa is Tier 2 (General) visa.

Visa Start Date: 22/5/2014
Visa End Date: 24/4/2019

I am 28 days short of 5 years on my Tier 2 visa, and my understanding is I would need to apply for Tier 2 - extension first and only then I am eligible to apply for ILR (is that correct)?

Also, recently I came across option of varying an application. Is it possible if I apply for Tier 2 extension on 10/4/2019 and then vary my application to ILR on 15/4/2019 (or slightly later date)? Will that be valid?

Or are there any other routes in which I don't have to pay the fees twice - for Tier 2 extension and then for ILR?

I have no long absences during my stay in the UK throughout this period and have no offences.