It is very easy to lie with figures.
In our parents generation 2.5 x salary was the norm for a mortgage and this was when interest rates were 15-18%.
Applying this metric suggests an income of €108k
Why is your figure so much higher?
I don’t know?
If you apply the 2.5x income rule at interest rates of 18% as you mention, you are talking of monthly repayments of over 4,000 a month on a 25 year mortgage of 270K.
I don’t see how that’s manageable/affordable.
Perhaps previous generations spent more than 35% of income on their mortgage in the early years!
If you make assumptions of 7% interest rates you most also need to make assumptions about wage growth.
Maybe in the old days. Interest rate rises from the ECB don’t necessarily mean wage inflation in poor little Ireland ;(
ECB interest rates are currently 1.5% with a stated target of maintaining inflation at 2%.
Wages increases in Europe are running at rates marginally in excess of this.
In the medium term interest rates inflation and wage growth in an economy are linked.
You’re assuming Ireland’s economy is nicely linked with the well performing parts of Europe.
Read the rest of this site 
Anyway, it’s probably a moot point, whatever way you shake it you’re still looking at wanting to earn at least 100K to buy that 300K house. The kind of houses you get right now for 300K are probably not the kind of houses that your average 6 figure salary earner is likely to want to entertain.
Dont go near the second one. I viewed it over a year ago and it looks like its falling down.