I've been drinking 3 different styles of Spanish cava over the holidays that I have been real impressed with. all $15 and under.
Loxarel Saniger Brut $9.99
Loxarel Cuvee Henri $14.99
Mont-Ferrant Brut Rose Cava was $15.99
All 3 were not too dry and were very well received by my party goers.
I've been drinking The Cuvee for the past 3 nights with dnner and it just goes down so easy. Nice apple scented nose.
Try Gruet Brut from New Mexico. I know it's available in NYC around $15. I worked in the wine business in NM and know the wines and the winemaker very well. Laurent Gruet is the son of French champagne producer G. Gruet et Fils. He and his business partner came to the US fully expecting to be making wine in California, but found southern NM to have the right weather and climate for champagne grapes so they set up shop there.
I think Gruet brut is the best US sparkler until you get to Roederer Estate range. The Blanc de Noirs is fruitier and seems less assertive than the brut. The brut is the one to buy. Gruet also makes a delicious sparkling rose in the same price range. Their vintage blanc de blancs is also outstanding and worth a try at about $27.
Walk into any quality wine retailer in Manhattan and ask for Cremants in that price range. Cremant is a broad category of sparkling wine, made in the Champagne method, that cannot be called Champagne because it comes from Limoux, Borgogne, etc.
I believe the best $15 brut Cremants are on par with Veuve Cliquot yellow label.