I don't particularly like Viking gas ranges, especially the ones that were built 15 years ago. I believe there are much better ranges out there. If cooking is something that you enjoy doing and that is an important part of your day, you'll appreciate spending the money on either a better gas range (e.g. Bluestar) or an induction range. If you don't really care all that much about cooking, you probably won't notice the improvements quite as much. For all its short-comings, and as much as it hurts me to admit this, a 15 year old Viking is still better than many low- to mid-range consumer brands.

All of the above is the rational basis that you should form your decision on. If you need a little bit of a push, then you are welcome to use the defective igniters as a pre-text for why you need to buy a new range. But realistically, you should be aware that igniters are disposable parts. They are meant to wear out, break, and get replaced. In fact, many people would consider this a DIY maintenance job.

Glow-bar igniters aren't particularly energy efficient, nor do they last all that long. But they do have an amazing safety record. They are a really simple design that tends to fail in a safe fashion. More elaborate and longer-lasting solutions (e.g. click igniters, standing pilot, ...) all are also more likely to result in accidental gas leaks, if/when the igniter fails. So, we are likely to be stuck with glow-bars for good.