Logitech G502 spectrum price
Where are you looking for your prices? The Logitech Gaming website lists the RRP of the Core as $99.95 and the Spectrum as $129.95.
Keep in mind that all the major online retailers here buy the Core in bulk since it's incredibly popular and can sell it at $65. I expect the same to be true of the Spectrum once there is enough supply to fill orders that can meet a similar demand/supply ratio. I do suspect that we'll still get hit with a price premium despite the US RRP being the same - likely because A - less supply as it's a new product and higher demand as a result, B - RGB 'premium', or C - straya tax.
GlassBomb has it right though, the MRSP/RRP can be the same but for the price delivered to consumers there will be a difference based on the retailer's profit margin and the other factors I outlined.
Edit: It's also possible that the RRP of the Core has dropped since release so, maybe they meant the RRP of the Spectrum is the same as the original RRP of the Core. Entirely possible but I'm too lazy to investigate further.