OK, sure, two years of upgrades/publishing sounds better.
The only possible problem is the perpetual license, in the very long term, could end up being a problem. For example, Microsoft are soon dropping support for XP, so everyone who got an "indefinite" license for Windows XP can't expect Microsoft to then fix problems or provide support or updates. If Microsoft did our "perpetual license forever" type thing, XP users (having paid for XP) have the right to get Windows 7 as an upgrade and all the support and fixes, which costs Microsoft money to provide. In short, that would cost Microsoft more than the customer paid, which is why Windows 7 is a separately purchased product.
So I'd suggest the "indie perpetual" is actually a 10-year license at �150 (which would be �200 by renewing normally). You save money compared to renewing and get the product for a very long time. When it expires you are not forced to stop using it.
It's just not long-term sustainable to give away licenses that last absolutely forever. Nobody does that!
Does that sound like a good compromise?