Holiday Inn goes as low as 48€ at times if you book as an IHG member prepaid.
Other hotels, Rantasipi, Cumulus on the same shuttle bus road are cheap too, but IMO you lose your precious sleep time if it is short. I would then rather sleep at Hilton (within short walk outside) or inside terminal 2 at GLO, but they are way more expensive.
With very short connection and low budget, the previously mentioned capsules are an option along with sleeping on the benches at airport which is 24h open. I have tried sleeping on bench once, the good side is that there is plenty of space available and nobody disturbes you, but the down side is that there are night flights arriving pax and cleaning machines etc which are noisy and the hallways echo a lot, disturbing your sleep more than the hard benches.