How did "spendy" become a popular adjective ?

I've heard the term used with increasing frequency in recent months, but discovered that it was discussed three years ago in an entry in the Macmillan dictionary:

Spendy has caught on as a catchy new synonym for expensive. Its appeal and correspondingly speedy journey into mainstream usage may have been galvanised by its form, i.e. like pricey and costly, spendy's meaning is instantly recognizable as a money concept (compare: price, cost, spend).

Though spendy is regularly used across the board as an informal and trendy alternative to expensive, its typical contexts of use are in relation to the purchase of desirable, luxury items, things which might have cost you an arm and a leg, but will give you lots of pleasure once you've got them. Typical examples of goods that might be described as spendy are designer clothes and jewellery, or electronic products such as large plasma screen TVs or digital SLR cameras...

The exact origins of spendy are unclear, with some arguing that it evolved from a blend of the words expensive and trendy, and others believing it to be an adjectival play on spend (taking inspiration from e.g. pricey, a derivative of price which was first attested in 1932).

I don't like the word.  I try not to be a prescriptivist when it comes to new additions to language, but in this case it just seems that the word is totally unnecessary when "expensive" would do just as well.