No, indeed.
I'll readily admit that I had no doubt whatsoever that you would succumb to the siren lure of something of the kind...........the only question outstanding in my mind was the simple age-old one of "When?" this act would actually - if inevitably - take place.
Some time ago, I read a fascinating article (in a normally less than riveting business & finance section of the newspaper) on how people treat incomes from different sources differently. Thus, your 'juicy' tax rebate is ear-marked for an entirely different sort of expenditure than, say, would be the case with a weekly, bi-weekly, or monthly paycheque. The 'juicy' rebate goes towards something memorable, and worthwhile; not just a source of pleasure, but often put towards something that you will treasure.
This is in no way a criticism: I remember purchasing my very first SLR camera from my first paycheque for correcting student term assignments (a solid fortnight's endless work) which came in the form of a very welcome lump sum, and was disbursed from a different source than funded my salary. Likewise, any income I ever made from books, articles, or radio work was viewed very differently than a salary from teaching, and spent accordingly.
Anyway, while it was an entirely predictable (I'd even say it was an inevitable purchase) that in itself, should add to, rather than detract from, the pleasure this purchase will undoubtedly bestow and confer on your overall well-being and caffeine sated happiness.
Oh, an update: Following my latest head & chest cold, I am now on the road to a full recovery. This morning, after a briefing (which I gave), I repaired to......well, I need not say exactly where, lest roars of ribald laughter greet any reference to 'the boys'. Suffice to say that three exquisite double espressos were consumed in short order.....