I've seen a fab cushion cut pink sapphire with halo of diamond ring in Tiffany & Co in Brown Thomas. Can't find the exact one on their website, but I think this is it. I've no clue of the price; not much point in asking since I wasn't buying! But if you're wandering down Grafton St, it used to be in the first display case you'd see (sort of a corner case) as you walk into the Tiffany area.
I used to work in Blue Nile & they don't have pink sapphires on the website that you can browse in the way they have diamonds. There are a few coloured (mostly yellow) diamonds on the website, but it'd be worth a call or email to ask if they could source you a pink sapphire. They use pretty much all stones in their jewellery, but they don't have such quick & easy access to a big library of coloured gems the way they do for diamonds (since that's their main product). The DJCs (diamond jewellery consultants) don't get paid commission, so it makes no difference to them what you buy. And I know the ones based in Dublin, all good helpful folks
& the head jeweller is an amazingly talented guy.
Voltaire do similar stuff to Blue Nile, and it's an Irish company (would be nice to support an Irish company!) I think they'll come to your house wherever you live & do consultations, fittings etc. Diamonds are their main product too, but I'd imagine they have the connections to source you a pink sapphire. And I think like BN, they fit the ring to your budget.
Other than these big players...
If you live near Dublin, there are lots of small independent jewellers in the Design Tower on Grand Canal Quay. My personal favourite is these two guys http://www.dacapo.ie/
They trained in the same place as the BN head jeweller (CCOI course in Kilkenny) & have (or had, could be sold) a gorgeous pink quartz with diamond halo ring in Design Yard a while ago. I never thought pink quartz was particularly nice til I saw that. They have some really spectacular jewellery in their showroom (& online too, really great use of coloured stones).
I've bought loose stones from Simon Phelan in Djinn on Wexford St. He sources them himself & does commissions, so could be another route. He sells his own designs & other people's stuff in his shop, so you could check out his style there.
Could pop into Project 51 on South William St. There are a few jewellers working on site there, and you can see some of their designs in the store, get an idea of their styles. http://www.project51.ie/
If you live near Kilkenny, there are amazing jewellers there.
Inga Reid http://www.ingareed.com/
Rudolph Heltzel & his son Christopher http://rudolfheltzel.com/
(if money was no object, I'd buy out his store!
Or if you wanted to support a new jeweller starting out, any of last year's Kilkenny graduates would love the commission! As many names as I can remember... some of them have websites, and I reckon they all have facebook pages where you can contact them. Or the Craft Council of Ireland would have contact info for them if not.
Ariane Tobin - in Carlow
Sara Jane Lynch - in Dublin
Lena Gratsova / Elena Vladimirovna on her FB - in Dublin
Aaron O'Sullivan - think he's studying in Birmingham, but might still do commissions
Gale Anderson - also studying in Bham, but might do a commission
Niamh Mulligan - could be in Oz
Sorcha OHorain - in the Workhouse Studio in Waterford, http://workhousestudios.com/
think she was student of the year last year! I've missed someone from this class... oh well
Loretta (Haughey) O'Sullivan (from the previous group)
Any of these guys should be able to design you something to suit your budget.
Well hopefully some of these folks can make you the ring of your dreams!