When I first took over purchasing for our maintenance department in 2020, I had a pretty straightforward strategy for Siemens PLCs and related electrical gear: find the lowest unit price and buy it. I figured our engineers knew what they needed, and my job was just to get it for the least money possible. That assumption lasted exactly three months.
In Q1 2021, I found a supplier offering Siemens S7-1200 controllers at a price that was, honestly, way better than our regular distributor. I was thrilled—thought I was saving the company a ton of money. I placed an order for 12 units. What I didn't check? Their invoicing system. They sent me a handwritten receipt. Finance rejected the entire expense. I ended up eating about $1,200 out of our departmental contingency fund. That was the day I started learning about total cost of ownership (TCO).
So here's what I now know: the quoted price for a Siemens PLC module is rarely the final price. TCO includes the unit price, yes, but also shipping, handling, potential rush fees, setup or programming support—and critically, the cost of your time. If you have to spend 4 hours chasing down a missing invoice, that's real money.
I manage roughly $150,000 annually across about 8 vendors for electrical and automation supplies. That's a lot of orders to process. In 2022, I did a vendor consolidation project and realized that three different vendors we used for PLC parts all sourced from Siemens anyway, but their pricing varied by up to 18% for identical part numbers (based on quotes I collected in Q2 2022; verify current pricing). The difference wasn't quality—it was their business model and service level.
Since that costly lesson in 2021, I've shifted how I evaluate suppliers. I still care about price, but I now use a simple checklist before placing any major order (say, over $500):
I now use a preferred distributor for most of our Siemens PLC orders—they're not the absolute cheapest on unit price, but their invoicing is reliable, shipping is consistent (3-5 business days, as of January 2025), and they've never made me chase a missing receipt. That peace of mind alone is worth the premium.
Speaking of Siemens PLCs, one thing I've noticed is how market data can affect buying decisions. According to recent industry reports (Source: Fortune Business Insights, 2024), Siemens and Rockwell Automation are the top two players in the global PLC market, with Siemens holding a significant share, especially in Europe and Asia. I've seen internal discussions where engineers prefer Siemens for its scalability and broad product range—but that doesn't mean every project needs a top-tier controller.
"The $600 Siemens S7-1200 might be overkill for a simple pump control. A basic smart relay could do the job for $150. But if you're building a system that needs to integrate with existing Siemens infrastructure, the TCO of a cheaper option includes compatibility risk."
This is the nuance that a pure 'lowest price' approach misses. When I started, I would have bought the cheapest option for everything. Now I ask: what's the total cost over the life of the equipment? That includes installation, programming, potential downtime, and compatibility with existing gear.
For our facility (about 200 employees in a mid-sized manufacturing plant), I standardize on a few key items:
But here's the thing: I still comparison shop. I just do it with my eyes open. For a recent order of Siemens PLC modules (circa Q3 2024), I got quotes from three vendors. The cheapest was $520 per unit. The middle was $575. The most expensive was $620. The cheapest vendor? No tax ID on the invoice. The middle vendor? Had a proper system. I paid the $55 premium per unit and slept better.
If you're an admin buyer or a small business owner looking to purchase Siemens PLCs or any electrical equipment, take it from someone who's made the mistake: the lowest quoted price is rarely the cheapest option. Seriously. Calculate the TCO.
Also, be aware that market data changes. Global PLC market share figures from 2023 may not reflect current trends—verify with up-to-date sources. I learned this when I cited a market share stat in an internal report and my engineer pointed out it was two years old. Oops.
Finally, don't be afraid to ask suppliers directly: 'Can you provide a quote that includes shipping, handling, and is your invoicing system electronic?' If they hesitate, that's a red flag. Trust me on this one.
Pricing is for general reference only. Actual prices vary by vendor, specifications, and time of order. Verify current rates before purchasing.