Moderate hotel in Dublin?

We stay in Dun Laoghaire, which is a town just outside of Dublin. Dun Laoghaire is on the DART commuter train line to the center of Dublin. In addition the town is connected by bus to the Dublin airport. We have stayed at the Windsor Lodge and Ophira B&Bs, both of which cost under $100 per night including breakfast.

We stayed at the Albany House a couple years ago around the middle of May. We just stayed one night and we had an early flight so we didn't get to have the breakfast. But it was nice. The location was great. It's just a block or so from St Stephen's Green and so very near Grafton Street also. It shows on booking.com as $185 but I didn't put in specific dates. We booked directly through their website, www,albanyhousedublin.com

I stayed at the Pembroke Townhouse, 90 Pembroke Rd in Dublin, summer of 2017. It is well within your price range. It is a nice facility. The only thing I didn’t like was that coffee and tea service is in the lobby, so you had to throw on some clothes to run downstairs for that first cup of tea in the morning. Other than that, clean, great staff and delicious breakfast.

Thx for the info on lodging they all seemed vgd. Unfortunately all are full for my schedule. So i must continue to search.

I stayed several nights at Anchor House B&B on Lower Gardiner Street in the city center, north of the Liffrey. I found it pleasant enough and quite satisfactory with a very convenient location to walk everywhere. Breakfast is free if you book directly on their own website. It is just a couple minutes walk to an airlink express airport bus stop to get to or from the airport. It should be within your price range or lower for most nights, but it varies.

We found the Annagh House in Clontarf on Dublin Bay to be a good value in May 2018. They have only 4 smallish, but clean and well-furnished, rooms.

https://www.annaghhouseclontarf.com/

There's a bus stop a block down the street with frequent buses in/out of central Dublin. About 15 minutes. John serves a hearty "full Irish" breakfast. A bonus for us was an excellent seafood restaurant a short walk from the B&B on a night when we didn't want to go back into the city. I punched some dates in the last week of May 2019 into the reservation window and it appears that they still have vacancy, well within your budget.

We stayed at Harcourt Hotel in Harcourt Street, about 10 min walking distance from St Stephens Green, Grafton Street, and Trinity College. It was among the more affordable places we considered, and we chose it because it's well away from the Temple Bar area. It's around the corner from the airport bus route.
The only drawback was nighttime noise from the bars on the block, from about 1 AM to 5 AM both nights (Fri and Sat). In daytime it looks like a normal quiet residential block, so the nightlife was quite unexpected! The hotel provided ear plugs on the nightstand without asking.

We found a reasonable Airbnb in Clontarf for about $100 per night.